diff --git a/src/common/libkvs/test/treeobj.c b/src/common/libkvs/test/treeobj.c
index 51cde252b11d..61c8a203bde3 100644
--- a/src/common/libkvs/test/treeobj.c
+++ b/src/common/libkvs/test/treeobj.c
@@ -742,6 +742,33 @@ void test_corner_cases (void)
     json_decref (symlink);
 }
 
+void test_hash (void)
+{
+    char buf[128];
+    json_t *o;
+
+    ok (treeobj_hash (NULL, NULL, NULL, -1) < 0
+        && errno == EINVAL,
+        "treeobj_hash fails with EINVAL on bad input");
+
+    o = json_object ();
+    ok (treeobj_hash ("sha1", o, buf, 128) < 0
+        && errno == EINVAL,
+        "treeobj_hash fails with EINVAL on non-treeobj");
+    json_decref (o);
+
+    o = treeobj_create_val ("foo", 3);
+
+    ok (treeobj_hash ("sha1", o, buf, 1) < 0
+        && errno == EINVAL,
+        "treeobj_hash fails with EINVAL on too small buffer");
+
+    ok (treeobj_hash ("sha1", o, buf, 128) == 0,
+        "treeobj_hash success");
+
+    json_decref (o);
+}
+
 int main(int argc, char** argv)
 {
     plan (NO_PLAN);
@@ -757,6 +784,7 @@ int main(int argc, char** argv)
     test_corner_cases ();
 
     test_codec ();
+    test_hash ();
 
     done_testing();
 }
diff --git a/src/common/libkvs/treeobj.c b/src/common/libkvs/treeobj.c
index dd3635a85b00..38c4947c4835 100644
--- a/src/common/libkvs/treeobj.c
+++ b/src/common/libkvs/treeobj.c
@@ -569,6 +569,32 @@ char *treeobj_encode (const json_t *obj)
     return json_dumps (obj, JSON_COMPACT|JSON_SORT_KEYS);
 }
 
+int treeobj_hash (const char *hash_name, json_t *obj, char *s, int size)
+{
+    char *tmp = NULL;
+    int rc = -1;
+
+    if (!hash_name || !obj || !s || size <= 0) {
+        errno = EINVAL;
+        goto error;
+    }
+
+    if (treeobj_validate (obj) < 0)
+        goto error;
+
+    if (!(tmp = treeobj_encode (obj)))
+        goto error;
+
+    if (blobref_hash (hash_name, (uint8_t *)tmp, strlen (tmp),
+                      s, size) < 0)
+        goto error;
+
+    rc = 0;
+ error:
+    free (tmp);
+    return rc;
+}
+
 /*
  * vi:tabstop=4 shiftwidth=4 expandtab
  */
diff --git a/src/common/libkvs/treeobj.h b/src/common/libkvs/treeobj.h
index b987b0a47028..3243280702bc 100644
--- a/src/common/libkvs/treeobj.h
+++ b/src/common/libkvs/treeobj.h
@@ -114,6 +114,11 @@ json_t *treeobj_decode (const char *buf);
 json_t *treeobj_decodeb (const char *buf, size_t buflen);
 char *treeobj_encode (const json_t *obj);
 
+/* Calculate hash of a treeobj
+ * Returns 0 on success, -1 on error with errno set
+ */
+int treeobj_hash (const char *hash_name, json_t *obj, char *s, int size);
+
 #endif /* !_FLUX_KVS_TREEOBJ_H */
 
 /*
diff --git a/src/modules/kvs/cache.c b/src/modules/kvs/cache.c
index d9f4f5c82c81..d1735113905a 100644
--- a/src/modules/kvs/cache.c
+++ b/src/modules/kvs/cache.c
@@ -137,7 +137,8 @@ int cache_entry_force_clear_dirty (struct cache_entry *hp)
     return -1;
 }
 
-int cache_entry_get_raw (struct cache_entry *hp, void **data, int *len)
+int cache_entry_get_raw (struct cache_entry *hp, const void **data,
+                         int *len)
 {
     if (!hp || !hp->valid)
         return -1;
diff --git a/src/modules/kvs/cache.h b/src/modules/kvs/cache.h
index c1b29d13572b..990b6c5babbc 100644
--- a/src/modules/kvs/cache.h
+++ b/src/modules/kvs/cache.h
@@ -79,7 +79,8 @@ int cache_entry_force_clear_dirty (struct cache_entry *hp);
  * cache_entry_set_raw() & cache_entry_set_treeobj() &
  * cache_entry_clear_data() returns -1 on error, 0 on success
  */
-int cache_entry_get_raw (struct cache_entry *hp, void **data, int *len);
+int cache_entry_get_raw (struct cache_entry *hp, const void **data,
+                         int *len);
 int cache_entry_set_raw (struct cache_entry *hp, void *data, int len);
 
 const json_t *cache_entry_get_treeobj (struct cache_entry *hp);
diff --git a/src/modules/kvs/commit.c b/src/modules/kvs/commit.c
index eb121c09974e..7c5dbeea306f 100644
--- a/src/modules/kvs/commit.c
+++ b/src/modules/kvs/commit.c
@@ -166,7 +166,7 @@ void commit_cleanup_dirty_cache_entry (commit_t *c, struct cache_entry *hp)
     if (c->state == COMMIT_STATE_STORE
         || c->state == COMMIT_STATE_PRE_FINISHED) {
         href_t ref;
-        void *data;
+        const void *data;
         int len;
         int ret;
 
@@ -236,9 +236,9 @@ static int store_cache (commit_t *c, int current_epoch, json_t *o,
         blobref_hash (c->cm->hash_name, data, len, ref, sizeof (href_t));
     }
     else {
-        if (kvs_util_json_hash (c->cm->hash_name, o, ref) < 0) {
+        if (treeobj_hash (c->cm->hash_name, o, ref, sizeof (href_t)) < 0) {
             saved_errno = errno;
-            flux_log_error (c->cm->h, "kvs_util_json_hash");
+            flux_log_error (c->cm->h, "treeobj_hash");
             goto done;
         }
     }
@@ -344,13 +344,14 @@ static int commit_unroll (commit_t *c, int current_epoch, json_t *dir)
         }
         else if (treeobj_is_val (dir_entry)) {
             json_t *val_data;
-            size_t size;
+            const char *str;
 
             if (!(val_data = treeobj_get_data (dir_entry)))
                 return -1;
-            if (kvs_util_json_encoded_size (val_data, &size) < 0)
-                return -1;
-            if (size > BLOBREF_MAX_STRING_SIZE) {
+            /* jansson >= 2.7 could use json_string_length() instead */
+            str = json_string_value (val_data);
+            assert (str);
+            if (strlen (str) > BLOBREF_MAX_STRING_SIZE) {
                 if ((ret = store_cache (c, current_epoch, val_data,
                                         true, ref, &hp)) < 0)
                     return -1;
diff --git a/src/modules/kvs/kvs.c b/src/modules/kvs/kvs.c
index 70c4900d4eec..80f2ff62370d 100644
--- a/src/modules/kvs/kvs.c
+++ b/src/modules/kvs/kvs.c
@@ -364,8 +364,8 @@ static void content_store_completion (flux_future_t *f, void *arg)
     (void)content_store_get (f, arg);
 }
 
-static int content_store_request_send (kvs_ctx_t *ctx, void *data, int len,
-                                       bool now)
+static int content_store_request_send (kvs_ctx_t *ctx, const void *data,
+                                       int len, bool now)
 {
     flux_future_t *f;
     int saved_errno, rc = -1;
@@ -424,7 +424,7 @@ static int commit_load_cb (commit_t *c, const char *ref, void *data)
 static int commit_cache_cb (commit_t *c, struct cache_entry *hp, void *data)
 {
     struct kvs_cb_data *cbd = data;
-    void *storedata;
+    const void *storedata;
     int storedatalen = 0;
 
     assert (cache_entry_get_dirty (hp));
@@ -1622,9 +1622,9 @@ static int store_initial_rootdir (kvs_ctx_t *ctx, json_t *o, href_t ref)
     int rc = -1;
     int saved_errno, ret;
 
-    if (kvs_util_json_hash (ctx->hash_name, o, ref) < 0) {
+    if (treeobj_hash (ctx->hash_name, o, ref, sizeof (href_t)) < 0) {
         saved_errno = errno;
-        flux_log_error (ctx->h, "%s: kvs_util_json_hash",
+        flux_log_error (ctx->h, "%s: treeobj_hash",
                         __FUNCTION__);
         goto decref_done;
     }
@@ -1638,7 +1638,7 @@ static int store_initial_rootdir (kvs_ctx_t *ctx, json_t *o, href_t ref)
         cache_insert (ctx->cache, ref, hp);
     }
     if (!cache_entry_get_valid (hp)) {
-        void *data;
+        const void *data;
         int len;
         assert (o);
         if (cache_entry_set_treeobj (hp, o) < 0) {
diff --git a/src/modules/kvs/kvs_util.c b/src/modules/kvs/kvs_util.c
index 52676b190f11..1683c7490022 100644
--- a/src/modules/kvs/kvs_util.c
+++ b/src/modules/kvs/kvs_util.c
@@ -27,68 +27,8 @@
 #endif
 #include <stdio.h>
 #include <stdlib.h>
-#include <errno.h>
-#include <unistd.h>
 #include <stdbool.h>
-#include <ctype.h>
-#include <flux/core.h>
-#include <jansson.h>
-
-#include "src/common/libutil/blobref.h"
-
-#include "types.h"
-
-char *kvs_util_json_dumps (json_t *o)
-{
-    /* Must pass JSON_ENCODE_ANY, can be called on any object.  Must
-     * set JSON_SORT_KEYS, two different objects with different
-     * internal order should map to same string (and reference when
-     * used by kvs_util_json_hash()).
-     */
-    int flags = JSON_ENCODE_ANY | JSON_COMPACT | JSON_SORT_KEYS;
-    char *s;
-    if (!o) {
-        if (!(s = strdup ("null"))) {
-            errno = ENOMEM;
-            return NULL;
-        }
-        return s;
-    }
-    if (!(s = json_dumps (o, flags))) {
-        errno = ENOMEM;
-        return NULL;
-    }
-    return s;
-}
-
-int kvs_util_json_encoded_size (json_t *o, size_t *size)
-{
-    char *s = kvs_util_json_dumps (o);
-    if (!s) {
-        errno = ENOMEM;
-        return -1;
-    }
-    if (size)
-        *size = strlen (s);
-    free (s);
-    return 0;
-}
-
-int kvs_util_json_hash (const char *hash_name, json_t *o, href_t ref)
-{
-    char *s = NULL;
-    int rc = -1;
-
-    if (!(s = kvs_util_json_dumps (o)))
-        goto error;
-    if (blobref_hash (hash_name, (uint8_t *)s, strlen (s),
-                      ref, sizeof (href_t)) < 0)
-        goto error;
-    rc = 0;
-error:
-    free (s);
-    return rc;
-}
+#include <string.h>
 
 char *kvs_util_normalize_key (const char *key, bool *want_directory)
 {
diff --git a/src/modules/kvs/kvs_util.h b/src/modules/kvs/kvs_util.h
index fce0264e0ed3..9e3f74e573dd 100644
--- a/src/modules/kvs/kvs_util.h
+++ b/src/modules/kvs/kvs_util.h
@@ -1,27 +1,5 @@
 #ifndef _FLUX_KVS_UTIL_H
 #define _FLUX_KVS_UTIL_H
-#include <jansson.h>
-
-#include "src/common/libutil/tstat.h"
-#include "waitqueue.h"
-#include "types.h"
-
-/* Get compact string representation of json object, or json null
- * object if o is NULL.  Use this function for consistency, especially
- * when dealing with data that may be hashed via kvs_util_json_hash().
- *
- * Returns NULL on error
- */
-char *kvs_util_json_dumps (json_t *o);
-
-/* returns 0 on success, -1 on failure */
-int kvs_util_json_encoded_size (json_t *o, size_t *size);
-
-/* Calculate hash of a json object
- *
- * Returns -1 on error, 0 on success
- */
-int kvs_util_json_hash (const char *hash_name, json_t *o, href_t ref);
 
 /* Normalize a KVS key
  * Returns new key string (caller must free), or NULL with errno set.
diff --git a/src/modules/kvs/lookup.c b/src/modules/kvs/lookup.c
index 2a97415ffbfb..c2302249e73b 100644
--- a/src/modules/kvs/lookup.c
+++ b/src/modules/kvs/lookup.c
@@ -636,7 +636,7 @@ static int get_single_blobref_valref_value (lookup_t *lh, bool *stall)
 {
     struct cache_entry *hp;
     const char *reftmp;
-    void *valdata;
+    const void *valdata;
     int len;
 
     if (!(reftmp = treeobj_get_blobref (lh->wdirent, 0))) {
@@ -707,7 +707,7 @@ static char *get_multi_blobref_valref_data (lookup_t *lh, int refcount,
 {
     struct cache_entry *hp;
     const char *reftmp;
-    void *valdata;
+    const void *valdata;
     int len;
     char *valbuf = NULL;
     int pos = 0;
diff --git a/src/modules/kvs/test/cache.c b/src/modules/kvs/test/cache.c
index 8c55671c0a41..fbf371a11a9c 100644
--- a/src/modules/kvs/test/cache.c
+++ b/src/modules/kvs/test/cache.c
@@ -84,7 +84,8 @@ void cache_entry_raw_tests (void)
 {
     struct cache_entry *e;
     json_t *o1;
-    char *data, *data2, *datatmp;
+    char *data, *data2;
+    const char *datatmp;
     int len;
 
     /* test empty cache entry later filled with raw data.
@@ -122,7 +123,7 @@ void cache_entry_raw_tests (void)
         "cache_entry_set_treeobj, silent success");
     o1 = NULL;
 
-    ok (cache_entry_get_raw (e, (void **)&datatmp, &len) == 0,
+    ok (cache_entry_get_raw (e, (const void **)&datatmp, &len) == 0,
         "raw data retrieved from cache entry");
     ok (datatmp && strcmp (datatmp, data) == 0,
         "raw data matches expected string");
@@ -176,7 +177,7 @@ void cache_entry_raw_tests (void)
     json_decref (o1);
     o1 = NULL;
 
-    ok (cache_entry_get_raw (e, (void **)&datatmp, &len) == 0,
+    ok (cache_entry_get_raw (e, (const void **)&datatmp, &len) == 0,
         "raw data retrieved from cache entry");
     ok (datatmp == NULL,
         "raw data is NULL");
@@ -274,7 +275,8 @@ void cache_entry_raw_and_treeobj_tests (void)
     struct cache_entry *e;
     json_t *o1, *otest;
     const json_t *otmp;
-    char *data, *datatmp;
+    char *data;
+    const char *datatmp;
     int len;
 
     /* test cache entry filled with raw data that is not valid treeobj
@@ -329,7 +331,7 @@ void cache_entry_raw_and_treeobj_tests (void)
         "cache_entry_create works");
     ok (cache_entry_set_treeobj (e, o1) == 0,
         "cache_entry_set_treeobj success");
-    ok (cache_entry_get_raw (e, (void **)&datatmp, &len) == 0,
+    ok (cache_entry_get_raw (e, (const void **)&datatmp, &len) == 0,
         "cache_entry_get_raw returns success for get treeobj raw data");
     ok (datatmp && strcmp (datatmp, data) == 0,
         "raw data matches expected string version of treeobj");
diff --git a/src/modules/kvs/test/commit.c b/src/modules/kvs/test/commit.c
index dc0b97ee7ab4..8f785e25894d 100644
--- a/src/modules/kvs/test/commit.c
+++ b/src/modules/kvs/test/commit.c
@@ -80,8 +80,8 @@ struct cache *create_cache_with_empty_rootdir (href_t ref)
 
     ok ((cache = cache_create ()) != NULL,
         "cache_create works");
-    ok (kvs_util_json_hash ("sha1", rootdir, ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", rootdir, ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
     ok ((hp = create_cache_entry_treeobj (rootdir)) != NULL,
         "create_cache_entry_treeobj works");
     cache_insert (cache, ref, hp);
@@ -631,8 +631,8 @@ void commit_basic_root_not_dir (void)
     /* make a non-dir root */
     root = treeobj_create_val ("abcd", 4);
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -699,8 +699,8 @@ void commit_process_root_missing (void)
     ok ((rootdir = treeobj_create_dir ()) != NULL,
         "treeobj_create_dir works");
 
-    ok (kvs_util_json_hash ("sha1", rootdir, rootref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", rootdir, rootref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     json_decref (rootdir);
 
@@ -797,16 +797,16 @@ void commit_process_missing_ref (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     /* don't add dir entry, we want it to miss  */
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -896,16 +896,16 @@ void commit_process_error_callbacks (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     /* don't add dir entry, we want it to miss  */
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -985,16 +985,16 @@ void commit_process_error_callbacks_partway (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1042,8 +1042,8 @@ void commit_process_invalid_operation (void)
     /* This root is an empty root */
     root = treeobj_create_dir ();
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1137,8 +1137,8 @@ void commit_process_invalid_hash (void)
     /* This root is an empty root */
     root = treeobj_create_dir ();
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1192,8 +1192,8 @@ void commit_process_follow_link (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
@@ -1201,8 +1201,8 @@ void commit_process_follow_link (void)
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
     treeobj_insert_entry (root, "symlink", treeobj_create_symlink ("dir"));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1259,8 +1259,8 @@ void commit_process_dirval_test (void)
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", dir);
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1317,16 +1317,16 @@ void commit_process_delete_test (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1372,8 +1372,8 @@ void commit_process_delete_nosubdir_test (void)
     /* This root is an empty root */
     root = treeobj_create_dir ();
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1426,16 +1426,16 @@ void commit_process_delete_filevalinpath_test (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1488,8 +1488,8 @@ void commit_process_bad_dirrefs (void)
     dir = treeobj_create_dir ();
     treeobj_insert_entry (dir, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
@@ -1499,8 +1499,8 @@ void commit_process_bad_dirrefs (void)
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dir", dirref);
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1570,8 +1570,8 @@ void commit_process_big_fileval (void)
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "val", treeobj_create_val ("42", 2));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1716,16 +1716,16 @@ void commit_process_giant_dir (void)
     treeobj_insert_entry (dir, "val0e00", treeobj_create_val ("E", 1));
     treeobj_insert_entry (dir, "valF000", treeobj_create_val ("f", 1));
 
-    ok (kvs_util_json_hash ("sha1", dir, dir_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", dir, dir_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, dir_ref, create_cache_entry_treeobj (dir));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (dir, "dir", treeobj_create_dirref (dir_ref));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1801,8 +1801,8 @@ void commit_process_append (void)
     treeobj_insert_entry (root, "val", treeobj_create_val ("abcd", 4));
     treeobj_insert_entry (root, "valref", treeobj_create_val ("ABCD", 4));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
@@ -1927,8 +1927,8 @@ void commit_process_append_errors (void)
     treeobj_insert_entry (root, "dir", treeobj_create_dir ());
     treeobj_insert_entry (root, "symlink", treeobj_create_symlink ("dir"));
 
-    ok (kvs_util_json_hash ("sha1", root, root_ref) == 0,
-        "kvs_util_json_hash worked");
+    ok (treeobj_hash ("sha1", root, root_ref, sizeof (href_t)) == 0,
+        "treeobj_hash worked");
 
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
diff --git a/src/modules/kvs/test/kvs_util.c b/src/modules/kvs/test/kvs_util.c
index 09c89e41a484..f731ea7f6ac4 100644
--- a/src/modules/kvs/test/kvs_util.c
+++ b/src/modules/kvs/test/kvs_util.c
@@ -2,17 +2,18 @@
 #include "config.h"
 #endif
 #include <stdbool.h>
-#include <jansson.h>
+#include <string.h>
 
 #include "src/common/libtap/tap.h"
 #include "src/modules/kvs/kvs_util.h"
-#include "src/modules/kvs/types.h"
 
-void test_norm (void)
+int main (int argc, char *argv[])
 {
     char *s;
     bool dirflag;
 
+    plan (NO_PLAN);
+
     s = kvs_util_normalize_key ("a.b.c.d.e", &dirflag);
     ok (s != NULL && !strcmp (s, "a.b.c.d.e") && dirflag == false,
         "kvs_util_normalize_key works on normal key");
@@ -57,96 +58,6 @@ void test_norm (void)
     ok (s != NULL && !strcmp (s, "."),
         "kvs_util_normalize_key transforms several standalone separators to one");
     free (s);
-}
-
-
-int main (int argc, char *argv[])
-{
-    json_t *obj;
-    href_t ref;
-    char *s1, *s2;
-    size_t size;
-
-    plan (NO_PLAN);
-
-    obj = json_object ();
-    json_object_set_new (obj, "A", json_string ("foo"));
-    json_object_set_new (obj, "B", json_string ("bar"));
-    json_object_set_new (obj, "C", json_string ("cow"));
-
-    ok (kvs_util_json_hash ("sha1", obj, ref) == 0,
-        "kvs_util_json_hash works on sha1");
-
-    ok (kvs_util_json_hash ("foobar", obj, ref) < 0,
-        "kvs_util_json_hash error on bad hash name");
-
-    json_decref (obj);
-
-    obj = json_object ();
-    json_object_set_new (obj, "A", json_string ("a"));
-    json_object_set_new (obj, "B", json_string ("b"));
-    json_object_set_new (obj, "C", json_string ("c"));
-
-    ok ((s1 = kvs_util_json_dumps (obj)) != NULL,
-        "kvs_util_json_dumps works");
-
-    /* json object is sorted and compacted */
-    s2 = "{\"A\":\"a\",\"B\":\"b\",\"C\":\"c\"}";
-
-    ok (!strcmp (s1, s2),
-        "kvs_util_json_dumps dumps correct string");
-
-    ok (kvs_util_json_encoded_size (obj, NULL) == 0,
-        "kvs_util_json_encoded_size works w/ NULL size param");
-
-    ok (kvs_util_json_encoded_size (obj, &size) == 0,
-        "kvs_util_json_encoded_size works");
-
-    ok (size == strlen (s2),
-        "kvs_util_json_encoded_size returns correct size");
-
-    free (s1);
-    s1 = NULL;
-    json_decref (obj);
-
-    obj = json_null ();
-
-    ok ((s1 = kvs_util_json_dumps (obj)) != NULL,
-        "kvs_util_json_dumps works");
-
-    s2 = "null";
-
-    ok (!strcmp (s1, s2),
-        "kvs_util_json_dumps works on null object");
-
-    ok (kvs_util_json_encoded_size (obj, &size) == 0,
-        "kvs_util_json_encoded_size works");
-
-    ok (size == strlen (s2),
-        "kvs_util_json_encoded_size returns correct size");
-
-    free (s1);
-    s1 = NULL;
-    json_decref (obj);
-
-    ok ((s1 = kvs_util_json_dumps (NULL)) != NULL,
-        "kvs_util_json_dumps works on NULL pointer");
-
-    s2 = "null";
-
-    ok (!strcmp (s1, s2),
-        "kvs_util_json_dumps works on NULL pointer");
-
-    ok (kvs_util_json_encoded_size (NULL, &size) == 0,
-        "kvs_util_json_encoded_size works on NULL pointer");
-
-    ok (size == strlen (s2),
-        "kvs_util_json_encoded_size returns correct size");
-
-    free (s1);
-    s1 = NULL;
-
-    test_norm ();
 
     done_testing ();
     return (0);
diff --git a/src/modules/kvs/test/lookup.c b/src/modules/kvs/test/lookup.c
index 081163f12a6a..34a423215c17 100644
--- a/src/modules/kvs/test/lookup.c
+++ b/src/modules/kvs/test/lookup.c
@@ -412,7 +412,7 @@ void lookup_root (void) {
     cache_insert (cache, valref_ref, create_cache_entry_raw (strdup ("abcd"), 4));
 
     root = treeobj_create_dir ();
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
     /* flags = 0, should error EISDIR */
@@ -517,7 +517,7 @@ void lookup_basic (void) {
     dirref_test = treeobj_create_dir ();
     treeobj_insert_entry (dirref_test, "dummy", treeobj_create_val ("dummy", 5));
 
-    kvs_util_json_hash ("sha1", dirref_test, dirref_test_ref);
+    treeobj_hash ("sha1", dirref_test, dirref_test_ref, sizeof (href_t));
     cache_insert (cache, dirref_test_ref, create_cache_entry_treeobj (dirref_test));
 
     dir = treeobj_create_dir ();
@@ -540,13 +540,13 @@ void lookup_basic (void) {
 
     treeobj_insert_entry (dirref, "valref_multi_with_dirref", valref_multi_with_dirref);
 
-    kvs_util_json_hash ("sha1", dirref, dirref_ref);
+    treeobj_hash ("sha1", dirref, dirref_ref, sizeof (href_t));
     cache_insert (cache, dirref_ref, create_cache_entry_treeobj (dirref));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dirref", treeobj_create_dirref (dirref_ref));
 
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
     /* lookup dir via dirref */
@@ -774,7 +774,7 @@ void lookup_errors (void) {
 
     dirref = treeobj_create_dir ();
     treeobj_insert_entry (dirref, "val", treeobj_create_val ("bar", 3));
-    kvs_util_json_hash ("sha1", dirref, dirref_ref);
+    treeobj_hash ("sha1", dirref, dirref_ref, sizeof (href_t));
     cache_insert (cache, dirref_ref, create_cache_entry_treeobj (dirref));
 
     dir = treeobj_create_dir ();
@@ -799,7 +799,7 @@ void lookup_errors (void) {
 
     treeobj_insert_entry (root, "dirref_multi", dirref_multi);
 
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
     /* Lookup non-existent field.  Not ENOENT - caller of lookup
@@ -1083,7 +1083,7 @@ void lookup_links (void) {
 
     dirref3 = treeobj_create_dir ();
     treeobj_insert_entry (dirref3, "val", treeobj_create_val ("baz", 3));
-    kvs_util_json_hash ("sha1", dirref3, dirref3_ref);
+    treeobj_hash ("sha1", dirref3, dirref3_ref, sizeof (href_t));
     cache_insert (cache, dirref3_ref, create_cache_entry_treeobj (dirref3));
 
     dir = treeobj_create_dir ();
@@ -1095,7 +1095,7 @@ void lookup_links (void) {
     treeobj_insert_entry (dirref2, "dir", dir);
     treeobj_insert_entry (dirref2, "dirref", treeobj_create_dirref (dirref3_ref));
     treeobj_insert_entry (dirref2, "symlink", treeobj_create_symlink ("dirref2.val"));
-    kvs_util_json_hash ("sha1", dirref2, dirref2_ref);
+    treeobj_hash ("sha1", dirref2, dirref2_ref, sizeof (href_t));
     cache_insert (cache, dirref2_ref, create_cache_entry_treeobj (dirref2));
 
     dirref1 = treeobj_create_dir ();
@@ -1104,13 +1104,13 @@ void lookup_links (void) {
     treeobj_insert_entry (dirref1, "link2valref", treeobj_create_symlink ("dirref2.valref"));
     treeobj_insert_entry (dirref1, "link2dir", treeobj_create_symlink ("dirref2.dir"));
     treeobj_insert_entry (dirref1, "link2symlink", treeobj_create_symlink ("dirref2.symlink"));
-    kvs_util_json_hash ("sha1", dirref1, dirref1_ref);
+    treeobj_hash ("sha1", dirref1, dirref1_ref, sizeof (href_t));
     cache_insert (cache, dirref1_ref, create_cache_entry_treeobj (dirref1));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dirref1", treeobj_create_dirref (dirref1_ref));
     treeobj_insert_entry (root, "dirref2", treeobj_create_dirref (dirref2_ref));
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
     /* lookup val, follow two links */
@@ -1280,18 +1280,18 @@ void lookup_alt_root (void) {
 
     dirref1 = treeobj_create_dir ();
     treeobj_insert_entry (dirref1, "val", treeobj_create_val ("foo", 3));
-    kvs_util_json_hash ("sha1", dirref1, dirref1_ref);
+    treeobj_hash ("sha1", dirref1, dirref1_ref, sizeof (href_t));
     cache_insert (cache, dirref1_ref, create_cache_entry_treeobj (dirref1));
 
     dirref2 = treeobj_create_dir ();
     treeobj_insert_entry (dirref2, "val", treeobj_create_val ("bar", 3));
-    kvs_util_json_hash ("sha1", dirref2, dirref2_ref);
+    treeobj_hash ("sha1", dirref2, dirref2_ref, sizeof (href_t));
     cache_insert (cache, dirref2_ref, create_cache_entry_treeobj (dirref2));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dirref1", treeobj_create_dirref (dirref1_ref));
     treeobj_insert_entry (root, "dirref2", treeobj_create_dirref (dirref2_ref));
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
     cache_insert (cache, root_ref, create_cache_entry_treeobj (root));
 
     /* lookup val, alt root-ref dirref1_ref */
@@ -1341,7 +1341,7 @@ void lookup_stall_root (void) {
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "val", treeobj_create_val ("foo", 3));
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
 
     /* do not insert entries into cache until later for these stall tests */
 
@@ -1454,17 +1454,17 @@ void lookup_stall (void) {
     treeobj_append_blobref (valref_tmp, valrefmisc2_ref);
     treeobj_insert_entry (dirref1, "valrefmisc_multi", valref_tmp);
 
-    kvs_util_json_hash ("sha1", dirref1, dirref1_ref);
+    treeobj_hash ("sha1", dirref1, dirref1_ref, sizeof (href_t));
 
     dirref2 = treeobj_create_dir ();
     treeobj_insert_entry (dirref2, "val", treeobj_create_val ("bar", 3));
-    kvs_util_json_hash ("sha1", dirref2, dirref2_ref);
+    treeobj_hash ("sha1", dirref2, dirref2_ref, sizeof (href_t));
 
     root = treeobj_create_dir ();
     treeobj_insert_entry (root, "dirref1", treeobj_create_dirref (dirref1_ref));
     treeobj_insert_entry (root, "dirref2", treeobj_create_dirref (dirref2_ref));
     treeobj_insert_entry (root, "symlink", treeobj_create_symlink ("dirref2"));
-    kvs_util_json_hash ("sha1", root, root_ref);
+    treeobj_hash ("sha1", root, root_ref, sizeof (href_t));
 
     /* do not insert entries into cache until later for these stall tests */